Carriage-wheel



odel.) Y

B. A; TREAT-8U E. S. PARMELEEQ GGGG IAGE WHEEL. I

No. 377,587.- Pa tented- Fb, 7, 1888."

' UNITED, STATES PATENT] OFFICE..-

BRYANT A. TREAT AND EDWIN S. FARMELEE, OF WALLINGFORD,

CONNECTICUT.

CARRIAGE-WHEEL.

SPECIFICATION forming part of Letters Patent No. 377,587, dated February 7,1888.

Application filed October 17,1887. Serial No. 252.528. (No model.) 7

To aZZ whom it may concern:

Be it known that we, BRYANT ,A. TREAT and EDWIN S. PARMELEE, of Wallingford, in the county of New Haven and State of Connecticutfhave invented a new Improvement in Carriage-Wheels; and we do hereby declare the following, when taken in connection with accompanying drawings and theletters of reference marked thereon, to be a full, clear, and exact description of the same-and which said drawings constitute part of this specification, and represent, in-

Figure 1, an edge view of the spoke, showing the improved tenon; Fig. 2, a portion of the hub, showing a mortise adapted to receive the tenon; Fig. 3, the same mortise after the spoke has been driven.

This invention relates to an improvement in the attachment of spokes to the hub of carriage-wheels, the object being to interlock the spoke with the wheel through the tenon. This interlocking has been accomplished as by cutting a recess across the tenon at the shoulder, or by making several transverse recesses across the tenon, to be embedded into the side of the mortise after the spoke was driven. The spoke has also been made of reverselyirregular shape upon its opposite sides, so as to embed to some extent in the sides of the mortise; but in all cases the expansion of the tenon into the side of the mortise has a tendency to expand the hub, because the thrust of the expansion of the tenon in the mortise is outward, and this tendency causes the hub to choke or split.

The object of this invention is to attain all the advantages of the expansion of the tenon within the mortise, but counteract. the radial expansion of the hub. To this endmy invention consists in making the tenon 'radially of elliptical shapethat is, so that the broadest part of the tenon is about midway of its length, and diminishing in thickness from that central point both toward the shoulder of the tenon and toward the inner end of the tenon.

The spoke A is of the usual form. Its tenon B is of usual length and of usual thickness at the shoulders and at its inner end; but the tenon gradually increases in thickness from the shoulder to about the center of its length, 1

' curving alike on both sides, and from that central point gradually diminishing to thein. ner end of the spoke, as seen in Fig. 1. The mortise in the hub is made of the usual, form, and corresponds in width throughontfto the width'of the narrower parts of the tenonthat is, the shoulder and the inner end.and as seen in Fig. 2. The tenon of the spoke should be first compressed to bring it to substantially the width of the mortise, then immediately driven into the mortise, it naturally expands to resume its original shape, as seen in Fig. 3. In so doing the expansion of the tenon from the center outward would tend to correspondingly expand the hub; but, from the central point inward the tendency is equally as strong to contract the hub, the result of which is that the expansive tendency upon the hub at one end of the tenon is counteracted by the tendency to contract the hubupon the 0pposite end, and consequently no detrimental effect upon the hub is produced by the expansion of the tenon, and the interlocking of the tenon and thehub is of the most perfect character, so much so that the direct withdrawal of the spoke from the hub is practically impossible.

It will be understood from the foregoing that we do not claim, broadly, an irregularshaped tenon on a spoke, adapted to be compressed to be driven into the hub, and then by its expansion to interlock with the hub; but

What we do claim is- The herein-described improvement in carriage-wheels, which consists in making the tenon of the spoke gradually increasing in thickness from the shoulders of the spoke to about midway of the length of the tenon, and from that midway point gradually diminishing toward the inner end of the spoke, substantially as described, the said tenon being adapted to be compressed into the mortise of the huband expand after its insertion to in terlock with the sides of the mortise.

BRYANT A. TREAT. EDWIN S. PARMELEE.

Witnesses:

FRED O. EARLE, LILLIAN D. KELSEY. 

